This 10" 30 lb no bounce medicine ball is perfect for core exercises and Crossfit workouts. Strength and power training benefits are enhanced with a single ball size spanning a wide range of weight. This means the same lifting-leverage factors will be applied consistently to the athleteís conditioning performance. D-Ball benefits are similar to Olympic lifting. However, D-Ball places more emphasis on the core where the transfer of power linkage of the three torso components, shoulders, core and hips is similar, but the ball is held off the centerline so the core works harder to support lift and stability.Yellow D-Balls are a golden yellow and do not bounce. They have a soft grip for a firm hold to move and throw in turn emphasizing both strength and speed. D-ball is the same size over an extended range of weight. The fact that the Yellow D-Balls do not bounce adds work as it must be picked up off the ground each time itís thrown.